Blade terminal for meters



y 1938. T. D. BARNES El AL 2,125,060

BLADE TERMINAL FOR METERS Filed May 11, 1935 WITNESSES: INVENTORS 6 W Thomas D. Barnes A? Walg r G. M y/fus RNEY Patented July 26, 1938 STATES PATENT oFIcE BLADE TERMINAL FOR METERS 'li'homas D. Barnes, Newark, and Walter G. Mylius, Summit, N. J., assignors to Westinghouse Electric & Manufacturing Company,

East

2 Claims.

The present invention relates to an improved method of mounting an electrical contact member, and more specifically, contemplates an improved mounting for a contact blade for watthour meters of the detachable type wherein a plurality of contact blades project from the base of the meter for engagement with contact sockets disposed in a receptacle upon which the meter is to be mounted.

The type of meter in connection with which the present invention is particularly adapted, is shown in Patent No. 1,969,499, issued August 7, 1934, to Bradshaw et al., and assigned to the Westinghouse Electric Manufacturing Company. In meters of this character, the contact blades extend through the base plate of the meter, the interior ends being connected to the windings of the meter mechanism, and the exterior ends being somewhat elongated for cooperation with suitable contact sockets or jaws in the support for the meter. It is to be understood, however, that the present invention is not limited to watthour meters, nor to the particular shape of the projecting portion of the contact member. I

In meter constructions of this character, diificulty has been found in providing a suficiently long electrical leakage path between the contact blade and the metallic meter base, and in preventing the entrance of moisture past the blade into the base of the meter.

It is an object of the present invention to provide an improved contact blade construction and, cooperating therewith, an improved gasket construction for mounting said contact blade in operative position projecting through the base of an electric meter.

In practicing the invention, a contact blade having a terminal portion extends through an aperture in the metallic base of the meter, and two bushing members are provided on opposite sides of the base surrounding the blade and secured in clamping relation with respect to the baseby means of a pin, or similar device, such that the terminal portion is held against one of the bushing members while the pin or like device engages the other. The confronting faces of the two bushing members are provided with interfitting portions, resulting in an irregular creepage path between the meter blade and base, affording increased electrical resistance to leakage currents and increased protection against the entrance of moisture into the meter casing. A felt washer may be placed between one of the bushing members and the meter base to afford a desired resiliency, and to further moisture-proof the blade mounting.

Referring to the drawing:

Figure 1 is a view in side elevation, with portions broken away, disclosing a watthour meter casing with contacts, mounted in accordance with the present invention, projecting from the base thereof; I

Fig. 2 is a view, in vertical section, taken along the line 11-11 of Fig. l;

Fig. 3 is a view, in plan, of a bushing member or washer shown in Fig. 2;

Figs. 4 and 5 are views, taken respectively on the lines IVIV and V-V of Fig. 3;

Fig. 6 is a plan view of another of the bushing members or washers shown in Fig. 2;

Fig. 7 is a view, in side elevation, of the construction shown in Fig. 6;

Fig. 8 is a view, partially in section, on the line VIII-VIII of Fig. 6; and

Figs. 9, 10 and 11 are side, end and top views of the terminal blade constructed in accordance with this invention.

Referring to Fig. 1, the invention may be applied to a watthour meter of the detachable type, including a metallic base 1, having a glass cover 2 secured thereto, in any suitable manner, as by clamping ring 3, in accordance with the disclosure of Patent 1,969,499 issued August 7, 1934 to W. M. Bradshaw et al. The cover and base are constructed to enclose a meter mechanism (not shown), the windings of which are to be connected to four contact blades 5. Each blade 5 projects through an aperture of substantially oval shape in the base i, and is maintained in position by bushing members 8 and 9 and gasket ID, as hereinafter described.

Referring to Fig. 2, each blade 5 is provided with an elongated body portion extending through an aperture in the base i and is provided with a terminal portion 52, which is formed by making a return-bend in the blade to constitute a loop for receiving a conductor. This construction is more clearly illustrated in Figs. 9, 10 and 11. The free end of the return-bent portion extends substantially at right angles to the body portion of the blade 5, and is provided with two extensions l4 adapted to project through suitable apertures in the body portion, and being deformed, as by a punching or riveting operation, to maintain the terminal portion in proper shape. A set-screw l6 (Fig. 2) may be inserted through a tapped hole in the terminal portion, as shown, to clamp the end of the conductor when it is inserted in the terminal. It has been found convenient, in some cases, to place the hole for set-screw IS on the opposite side of the terminal from that shown.

or in the top of the terminal, depending upon the requirements of a particular installation.

A bushing comprising members 8 and 9, and a gasket Ill of resilient material, such as felt, are disposed about the body of the blade 5, as indicated in Fig. 2, and a cotter pin E8, or the like is inserted through a small aperture i9 (Fig. 9) in the blade. Accordingly, the assembly is clamped between the blade terminal i2 and the cotter pin l8 with the base I between the bushing members 8 and 9.

Referring to Fig. 3, the bushing member 9 is provided with a central aperture 20 proportioned to tightly embrace the blade 5 and has a projecting central portion on one side thereof adapted to extend into the aperture in the base I.

The gasket ID, of felt or other fibrous resilient material, may be disposed between the peripheral edge of the washer 9-and the base I. This gasket assists in preventing the entrance of moisture into the meter case, and affords a more or less resilient mounting for the blade 5 to permit a limited lateral movement of the end of the blade so that it may readily be inserted into its contact socket or jaw even though not in exact alignment therewith as a result of manufacturing discrepancies.

The bushing member 8, referring to Figs. 6, '7 and 8 comprises a base portion having an opening 22 therein for tightly surrounding the blade 5, and on the side thereof to be disposed against the base i there is provided a flange having external dimensions such that it substantially fills the aperture in the base I, and

internal dimensions such that it may receive he enlarged portion on the confronting face of the member 9, in snug-fitting relation.

As shown in Fig. 2, the two members 8 and 9 are in inter-engaging or substantially telescopic relation, and the electrical creepage distance from the blade 5 to the base I is over an irregular path, substantially greater than if a bushing construction of a usual type is employed. The irregular contour of the confronting faces of the two members 9 and i renders it difficult for moisture or foreign matter to enter the inside of the meter casing, which function is further assisted by the felt gasket Ill.

Each bushing member 8 is provided with a shield 24 which, in the present embodiment, is molded integrally with the body portion and is provided with two angular portions 26 for greater structural strength. As indicated in Figs. 1 and 2. when the assembly is in operative position, the shield portions 24 extend substantially parallel to the blades 5 and are disposed in such position that the blades 5 will be protected against contact with the supporting receptacle or structure when the meter is being inserted or removed therefrom.

The bushing members 8 and 9 may be of any suitable insulating material, but we prefer to make them of a molded phenolic condensation product, or similar material.

Although the invention has been described with specific reference to an electric meter, quite obviously it may be used in conjunction with a casing, of the type shown, for enclosing any electrical instrumentality, and in fact, it is within the scope of the invention that it shall apply to any type of structure where it is desired to mount a conducting member extending through an aperture in an electrically conducting support of any kind.

Various modificationsmay be made in the construction shown and described, and it is desired that only such limitations shall be placed upon the invention as are disclosed by the prior art and set forth in the appended claims.

We claim as our invention:

1. In an encased electro-responsive device having a flat terminal blade of conducting material, means for mounting said blade to project through an opening in said casing comprising a bushing member having an upstanding flange proportioned to extend through said opening and to conform to the edges thereof and a flange at right angles thereto confronting the casing around said opening, a second bushing member on the opposite side of said casing having a raised central portion nested within the depression formed by said upstanding flange and a laterally extending portion overlying said up-' standing flange and extending beyond it, a slot extending centrally through each of said bushing members for receiving said blade, resilient means for maintaining said second bushing member out of contact with the edge of said upstanding flange, and means cooperating with the terminal blade for maintaining said bushing members and blade in operative position.

2. In an encased electro-responsive device having a flat terminal blade of conducting material, means for mounting said blade to project through an opening in said casing comprising a bushing member having an upstanding flange proportioned to extend through said opening and to conform to the edges thereof and a flange at right angles thereto confronting the casing around said opening, a second bushing member on the opposite side of said casing having a raised central portion nested within the depression formed by said upstanding flange and a laterally extending portion overlying said upstanding flange and extending beyond it, a slot extending through said raised central portion and said first named bushing member for receiving said blade, and a washer of resilient material, being greater in thickness than the height of that portion of the upstanding flange exposed beyond the face of the casing, surrounding said exposed portion, and means cooperating with the terminal blade for maintaining said bushing members, washer and blade in operative position.

THOMAS D. BARNES. WALTER G. MYLIUS. 

